misc/ldd: initial commit of python ldd script

1 files changed, 95 insertions, 0 deletions

diff --git a/misc/ldd/ldd.py b/misc/ldd/ldd.py
new file mode 100755
index 0000000..afb03b6
--- /dev/null
+++ b/misc/ldd/ldd.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+
+import sys
+import re, glob
+from optparse import OptionParser
+
+from elftools import __version__
+from elftools.common.exceptions import ELFError
+from elftools.common.py3compat import bytes2str
+from elftools.elf.elffile import ELFFile
+from elftools.elf.dynamic import DynamicSection
+
+class ReadElf(object):
+    def __init__(self, file):
+        """ file: stream object with the ELF file to read
+        """
+        self.elffile = ELFFile(file)
+
+    def display_dynamic_dt_needed(self):
+        """ Display the dynamic DT_NEEDED contained in the file
+        """
+        for section in self.elffile.iter_sections():
+            if not isinstance(section, DynamicSection):
+                continue
+
+            for tag in section.iter_tags():
+                if tag.entry.d_tag == 'DT_NEEDED':
+                    sys.stdout.write('\t%s\n' % bytes2str(tag.needed) )
+
+
+def ldpath(ld_so_conf='/etc/ld.so.conf'):
+    """ Generate paths to search for libraries from ld.so.conf.  Recursively
+        parse included files.  We assume correct syntax and the ld.so.cache
+        is in sync with ld.so.conf.
+    """
+    with open(ld_so_conf, 'r') as path_file:
+        lines = path_file.read()
+    lines = re.sub('#.*', '', lines)                   # kill comments
+    lines = list(re.split(':+|\s+|\t+|\n+|,+', lines)) # man 8 ldconfig
+
+    include_globs = []
+    for l in lines:
+        if l == '':
+           lines.remove('')
+        if l == 'include':
+            f = lines[lines.index(l) + 1]
+            lines.remove(l)
+            lines.remove(f)
+            include_globs.append(f)
+
+    include_files = []
+    for g in include_globs:
+        include_files = include_files + glob.glob('/etc/' + g)
+    for c in include_files:
+        lines = lines + ldpath(c)
+
+    return list(set(lines))
+
+
+SCRIPT_DESCRIPTION = 'Print shared library dependencies'
+VERSION_STRING = '%%prog: based on pyelftools %s' % __version__
+
+def main():
+    optparser = OptionParser(
+        usage='usage: %prog <elf-file>',
+        description=SCRIPT_DESCRIPTION,
+        add_help_option=False, # -h is a real option of readelf
+        prog='ldd.py',
+        version=VERSION_STRING)
+    optparser.add_option('-h', '--help',
+        action='store_true', dest='help',
+        help='Display this information')
+    options, args = optparser.parse_args()
+
+    #if options.help or len(args) == 0:
+        #optparser.print_help()
+        #sys.exit(0)
+
+    for f in args:
+        with open(f, 'rb') as file:
+            try:
+                readelf = ReadElf(file)
+                if len(args) > 1:
+                    sys.stdout.write('%s : \n' % f)
+                readelf.display_dynamic_dt_needed()
+            except ELFError as ex:
+                sys.stderr.write('ELF error: %s\n' % ex)
+                sys.exit(1)
+
+    lines = ldpath()
+    print(lines)
+
+
+if __name__ == '__main__':
+    main()